Process of making the disodium salt of 2-carboxy-phenyl-sulfuric acid



Patented Aug. 9, 949 a 2,478,834

[ UNITED smnzs rnocnss OF MAKING THE DIsoniUMsAnr or 2-CARBOXY-PHENYL-SULFURIC ACID.

Jacques Parrod, Paris, and Victor Armand, Montrouge, France, .assignors to Societe Generale dApplications Therapeutiques Theraplix, Paris, France, a French company No Drawing. Application November 13, 1946,- Serial No. 709,438. In France October 17, 1946 2 Claims. (Cl. 260-457) 1 2 The invention relates to a new arylsulfonate, OOOGHS viz. the disodium salt of 2 carboxy-phenyl-sul- 80311 H: phuric acid, or sodium salicylsulphate, NBOH o g -11:, 110

oso Na (1) 11 0 CH: Ha um 5 COONa 2) 000cm S O and the process of preparation thereof. |0311 The invention is also concerned with the proc- 7 N801 ess of preparation of other salts of the 2.carbon- 10 E30 CH: Ha

phenyl-sulphuric acid.

Applicants found that salicylsulphates can be readily prepared with high yields by preparing The prec pitated sodium chloride is removed by fi t an alkyl salicylsulphate and p ifyi the centrifugatm-n from the solution which is placed alkyl group by the base corresponding to the salt agam the reactlfm Vessel {14nd admlxed Wlth to be prepared 21 kg. sodium hydroxide added in successive frac- The f ll i example illustrates the manner tions. Stirring is continued for several hours. of carrying out the invention, as applied to the 000cm preparation of the sodium salt. $103K xample O/N -CQH5 ZNS-OH H 0 OH 32 kg. of chlorosulphonic acid are poured in a. a 3 500 1. reaction vessel, provided with a stirring device and a cooling jacket. The mass is cooled COONE CH down to 0 C. and 41 kg. of dimethylaniline are 25 added in small fractions, while stirring, care bea fl 3 11 COBB-III 2O ing taken to keep the temperature of the mix- CHa ture below 0 C. The reagents condense into dim th 1 ilin chlorosul honate e y an e p The precipitate thus formed. is separated by C1SO3H+ (CH3) 2NCsH5 C1SO3HN(CH3)2CsI-I5 e t ifug ti and urifi d by boiling t 95 Upon completion of the reaction, 38.3 kg. of o methylsalicylate, previously admixed with 30.5 Sodlllm sallcylsulphate S a WhIte powder, havkg. dimethylaniline, are added in small fractions. ing t following a acteristics: When the reaction is completed, the temperature Molecular Weight: 262

is allowed to rise to 30 C. while stirring is connot measurable due to thermal decompo tinued for several hours. smons The following reaction takes place: Solubility in cold water; 5 c o 0 CH3 Solubility in hot water: 200% H035 pH of the 10% solution: 9.4. OH k gf Cab-1f A test with iron perchloride proves the absence 0 of free salicylic acid.

Said product may be used for curing rheuma- (300GBa tisms, where it advantageously replaces the sali- 3 cylates, generally used; in equivalent doses, it is H91 better tolerated by the organism.

/ It is conditioned, as salicylates, in various pharmaceutical forms (ampulas, tablets) at the usual doses for salicylates.

3001. ethanol (95) are first added to the mix- Obviously, the invention is not limited to the ture, and then 14 kg. of sodium hydroxide are detail above described given solely by way of added by fractions. example.

H30 CH H Having now described our invention what we claim as new and desire to secure by Letters Patentis:

1. A process of preparing the disodium salt of 2 carboxy-phenyl-sulphuric acid, which comprises reacting chlorosulphonic acid with dimethylaniline, treating the dimethylaniline chlorosulphonate thus obtained with a lower alkylsalicylate in the presence of sufllcient dimethylaniline to take up the liberated hydrochloric acid and reacting therewith sodium hydroxide in alcoholic medium to precipitate sodium chloride and saponify the alkyl salicylsulphate.

2. A process of preparing the disodium salt of 2 carboxy-phenyi-sulphuric acid, which comprises reacting chlorosulphonic acid with dimethylaniline, treating the dimethylaniline chlorosulphonate thus obtained with a lower alkyl- REFERENCES CITED The following references are of record in the file of this patent:

Chemical Abstracts, Loeper et al., vol. 39, page 5325, 1945. 

